The invention relates to a household appliance, in particular a household dishwasher, washing machine, clothes dryer or the like, having one or more electrical components of an air drying device and/or fluid heating device, which are connected to an electrical energy supply network (EN).
In order for example to dry items being washed in the wash compartment of a household dishwasher, said items having been sprayed with wash liquor fluids according to one or more rinse and/or cleaning processes during a run through a dishwashing program, after a final drying step, rinse aid fluid, in particular water containing rinse aid, is generally heated in the preceding final rinse step with the aid for example of a flow-through heater or a heat exchanger as the fluid heating device in the wash liquor circulation circuit of the dishwasher, to such a high temperature that the items sprayed with said heated rinse aid fluid dry automatically in the drying step that follows the end of the final rinse process due to inherent heat drying. Such inherent heat drying of the items being washed therefore requires a sufficiently large quantity of heat to be transferred to the items being washed in the final rinse step before the drying step, so that the inherent heat of the items being washed, which has built up as said items underwent the hot final rinse, is sufficient to evaporate the rinse aid fluid adhering to the items, in particular water containing rinse aid, due to the heat stored in the items being washed. The moist air thus produced is generally conducted by way of one of more condensation surfaces in the wash compartment, from which the moisture from the air condenses. This condensed water is either conducted in the wash compartment or into special collectors.
A sorption drying apparatus for drying items being washed in a dishwasher is also known from DE 10 353 577 A1. In the subprogram step “Dry” of the respective dishwashing program of the dishwasher to dry items being washed moist air from its wash compartment is conducted continuously by means of a fan through the sorption column of the sorption drying apparatus, with moisture being extracted from the air passing through due to condensation by its reversibly dehydratable sorption drying material. The air thus dried is fed back into the wash compartment of the dishwasher where it is reloaded with moisture from the water vapor in the wash compartment and fed back again to the circuit of the sorption drying apparatus. For the regeneration, i.e. desorption, of the sorption column, its reversibly dehydratable sorption drying material is heated to very high temperatures by means of an air heating unit. Water stored in this sorption drying material then exits in the form of hot water vapor and is conducted by an air flow generated by means of the fan into the wash compartment. This allows a wash liquor, an item being washed that is present in the wash compartment and/or the air present in the wash compartment to be heated during the performance of for example a rinse and/or cleaning process of a newly started dishwashing program. This allows energy-efficient cleaning and drying of items being washed.
To avoid local overheating of the drying material of the sorption column during the desorption process a heater is disposed upstream of the air inlet of the sorption column in the flow direction of the air in DE 10 2005 004 096 A1 for example.
Furthermore in some dishwashers drying devices in the form of separate heat sources, e.g. hot air fans, are used in the wash compartment to heat the moist air mixture there during the drying process so that the air in the wash compartment can absorb a larger quantity of moisture.
In addition to the field of household dishwashers such air drying devices and/or fluid heating devices are also used in household washing machines, clothes dryers, washing machines or the like.
A perfect drying performance, in particular for example for drying rinse-moist or wet items being washed in a household dishwasher, with a thermal air drying device requires a certain minimum input of heat energy into the air flow to be heated in each instance. However at the same time for reasons of energy efficiency and energy saving is it desirable for a maximum heat energy input not to be exceeded for the air drying process. The same requirements are also specified for the fluid heating device when heating a fluid, e.g. wash liquor fluid in a dishwasher or washing fluid in a washing machine.
In practice a plurality of operating parameters of the respective air drying device or fluid heating device can influence the heat energy input into an air flow or a fluid brought about in each instance. Parameter constellations can occur here, with which the functions, desired performance characteristics, in particular energy efficiency and in some instances also operating safety of the air drying system or the fluid heating system can be adversely affected.